use non-commercial version of fluent assertions

Author: MaximTkachenko

test/Parsers.Tests.csproj

@@ -6,7 +6,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="FluentAssertions" Version="8.7.1" />
+    <PackageReference Include="FluentAssertions" Version="[7.0.0]" />
     <PackageReference Include="Microsoft.Net.Compilers.Toolset" Version="4.14.0">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>